Out of the given four alternatives, select the one which represents the correct Tadbhav form of the given Tatsam word.
"मक्षिका"

The word 'मक्षिका' is a classical Sanskrit (Tatsam) word, and its evolved colloquial Hindi (Tadbhav) form is मक्खी (housefly).
Other combinations:

* मोर $\to$ Tatsam: मयूर
* भौंरा $\to$ Tatsam: भ्रमर
* मेंढक $\to$ Tatsam: मण्डूक